Small Group: Acute Renal Failure Flashcards
What is the formula for clearance?
Cl = ([Urine]/[Plasma]) x average rate of urine production
Clearance is __________.
the volume of blood that is cleared of something per minute
What are rigors?
Sudden feelings of chills accompanied with rising temperature
Creatinine clearance is an ___________-estimation of clearance because it is secreted. Urea is an ______-estimation of clearance because it is absorbed.
over; under
Hypotension can cause renal acute-kidney injury because ___________.
ischemia can kill the tubular cells
What is FENa?
FENa is the fraction of excreted sodium
What is the formula for FENa?
FENa = ([urine sodium]/[plasm sodium]) / ([urine creatinine]/[plasma creatinine]) x 100
FENa will be greater than 2 in __________ disorders.
intrinsic
FENa will be less than 1 in ___________ disorders.
pre-renal
FENa will start out less than 1 and move to greater than 2 in ____________ disorders.
post-renal
Recall that angiotensin II affects the _________ arteriole.
efferent
Why does angiotensin II cause constriction in the efferent arteriole?
Hypovolemia decreases the pressure of the glomerulus. The body constricts the efferent arteriole to increase GFR pressure and preserve filtration.
Rhabdomyolysis causes ___________ kidney injury.
Intrinsic - > tubular
What is CPK?
Creatine phosphokinase
Other than ultrasound/imaging, what are some ways to look for obstructive renal disease?
Place a catheter after the patient has voided. If the reserve volume is greater than 150 ml, then obstruction is likely. Also, catheters should relieve the acute-renal failure symptoms.
Why does recovery from obstructive renal disease tend to go down the longer the obstruction is in place?
Because the reduction in single-nephron glomerular filtration rate causes afferent arteriole vasoconstriction. Prolonged vasoconstriction leads to ischemic injury.
Which arteriole does angiotensin II induce vasoconstriction in?
The efferent (to maintain glomerular pressure)
Although most membranous nephropathy is idiopathic, about 1/3 of cases are associated with these diseases: _____________.
SLE HBV HCV Heavy metal poisoning Cancer Gold
All those with nephrotic proteinuria should receive __________.
low-salt diets, ACE inhibitors, and BP-controlling agents
What is a differential diagnosis for nephritic syndrome?
Anti-GBM disease/Goodpasture's Vasculitis Post-infectious GN Lupus MPGN IgA nephropathy
What serological test can direct the diagnosis to MPGN?
Hepatitis titers
How is IgA nephropathy treated?
ACE inhibitors and steroids
How is Wegener’s treated?
Rituximab
Steroids
Cyclophosphamide
Plasma exchange
